Turnbuckle



March 8, 1955 w HESS 2,703,723

TURNBUCKLE Filed Dec. 1, 1952 INVENTOR ATTORNEY United States Patent Oflice 2,703,723 Patented Mar. 8, 1955 TURNBUCKLE William M. E. Hess, Point Pleasant, N. J. Application December 1, 1952, Serial No. 323,382 4 Claims. (Cl. 287-60) This invention relates to turnbuckles of general application for adjusting the tension of rods, wires, cables and the like, as in connection. with the rigging of sailboats and control linkage for aircraft and other machines. More specifically, the invention relates to a novel construction for turnbuckles which facilitates taking up slack and setting the desired tension in the connected members; and also assures'that the turnbuckle will not work loose due to vibration and the like.

Turnbuckles of ordinary form are subject to certain limitations, inconveniences and drawbacks, as for example, a separate wrench is usually required to actuate the turnbuckle to change its tension, and often a wrench of the proper size is not at hand when needed. Furthermore, it is highly advantageous to have wrench means of proper size for setting the'turnbuckle to provide proper tension, thus avoiding the danger that the turnbuckle or connected members will be damaged or broken by overloading beyond their capacity. Moreover, turnbuckles used to tension the rigging of a sailboat are likely to work loose due to vibration set up by the wind, causing the risk of failure of the rigging at some critical time.

The main objects of the invention are to overcome the limitations of turnbuckles of the prior art by providing quick acting take-up means of improved form for taking up slack and setting the proper tension in the connecting wires or the like; to provide a unitary turnbuckle which incorporates a lever part of suitable size adapted to make adjustment of the screw means at any time, simply by manipulation without the need for accessory tools; and to provide a toggle device for locking the screw means in positive manner merely by moving the aforesaid lever part to the locking position, and unlocking same by merely moving that part to the unlocked position.

A further object is to provide a turnbuckle of improved form which is simple and economical in construction, thoroughly practical in application, and reliable in operation.

An illustrative embodiment of this invention in the accompanying drawings, in which:

Fig. I is a side longitudinal view of the turnbuckle in which the lever part is in its normal locked position.

Fig. II is the top view thereof.

Fig. III is the bottom view thereof.

Fig. IV is similar to Fig. I, except the lever is shown in its unlocked and fully open position.

Fig. V is a detailed view in part section of one end of the turnbuckle showing the device for locking the screw means in any set position.

In the construction shown in the drawings the turnbuckle assemblage embodies a turnbuckle proper and a combined wrench and locking device which serves to adjust the screw means and also to lock it in ad usted position. The turnbuckle proper comprises an elongated body part or tubular nut 1, externally tapered and mternally threaded at both ends, and two screw parts 2 and 2', commonly called stub ends, having inner end portions with external screw threads complemental to those of the nut 1, and mating therewith. The stub ends 2 and 2', may be formed to provide a loop as shown, or a hook, eyelet, clevis, etc. As in all turnbuckles, the screw threads at one end of the nut 1, are right-handed and at the other end they are left-handed, so that when the nut is turned relative to the screw parts 2 and 2', these parts are drawn together or pushed apart by screw action, depending on the rotary direction in which the nut is turned. For maximum strength of the screw connections, the threads of the nut 1, and on the stub ends 2 and 2', should have a tight but easy working fit. The not 1, is therefor preferably formed with a close butted open seam or slit .9, extending longitudinally-see Fig. III-to facilitate obtaining such a fit during manufacture; because when the screw tap is entered into the nut to cut the threads, the nut, being resilient, opens somewhat, and after the tap is removed, springs back to normal size, leaving the tapped hole undersize. Hence, when the stub ends are assembled in the nut, the threads in the latter grip those in the former in elastic engagement, thus providing a tight but easy working fit as required.

The novel combined wrench and locking device comprises a lever 3, hinged on the middle of the nut 1, by means of a hinge pin 4, held tight in a hole passing diametrically through the nut 1, and a toggle linkage device, extending generally along the length of the nut 1. The lever 3, consists of a handle portion 3a, and a bifurcated spanner portion 3b, which straddles nut 1, and pivots on hinge pin 4. The spanner portion 3b, has two turned down ears of generally disc-like shape with a central hole in each fitting on hinge pin 4. Each ear is provided with a pair of diametral crank pins 5, located at the ends of the diameter of a circle whose center coincides with the axis of hinge pin 4. This arrangement enables the nut 1 to be turned about its axis by means of lever 3, which latter thus constitutes a wrench.

The device for locking the threaded connections at any position of adjustment of nut 1, comprises a pair of ferrules 7 and 7', one at each end of nut 1, each having a tapered bore complemental to the tapered ends of nut 1; and two pairs of links 6. Each pair of links is hinged at their outer ends to studs 8, located on diametrically opposite sides of ferrules 7 and 7'-see Fig. Vand at the inner end to one of the crank pins 5, carried by lever 3. The inner ends of the links have a circular enlargement or boss having a diameter such that the edge of the boss comes into sliding contact with hinge pin 4, the ends of which project beyond the ears of lever 3. The purpose of this feature is that when the toggle device is being closed to draw the ferrules tight on the nut, the link ends slide around hinge pin 4, thus relieving the crank pins from strain.

The operation of the turnbuckle is as follows: To adjust the tension, lever 3 is moved to the fully open position as shown in Fig. IV and then manually swung in one direction or the other around nut 1, until the desired tension adjustment is obtained. Then lever 3 is closed toward nut 1, as shown in Fig. 1, whereupon crank pins 5 pull the inner ends of links 6 around hinge pin 4, thus drawing ferrules 7 and 7' tightly over the tapered ends of nut 1. Ferrules 7 and 7' cause the resilient ends of the nut 1 to contract slightly and thereby the threads in the nut to bind the threads on stub ends 2 and 2', effectively locking the threaded connections against displacement by vibration. By comparing Fig. IV with Fig. I it becomes evident that in closing lever 3 against ferrule 7 the bosses on links 6 slide around hinge pin 4 beyond the toggle position. Consequently, when lever 3 is closed, there is a tension in links 6 which tends to hold lever 3 in normal locked position. However, stud 9 fixed in ferrule 7 and projecting through a hole in lever 3 is provided for securing lever 3 in locked position if desired. A cotter or safety wire, not shown, can be inserted in the small hole in stud 9 to hold lever 3 positively in locked position.

This turnbuckle can be used to advantageon sailboats and in other marine applications, and also in airplanes, where lightness, strength, reliability and security are requisite.

Although but one specific embodiment of this invention is herein shown and described, it will be understood that some details of the construction shown may be altered or omitted without departing from the scope and teaching of this invention as defined in the following claims.

I claim:

l. A self locking turnbuckle comprising a tubular nut having a bore with oppositely inclined internal threads and having externally tapered portions at opposite ends,

a pair of screw parts, each having an end portion with external threads fitting the aforesaid internal threads, a pair of ferrules each having a tapered bore comple mental to the aforesaid tapered end portions, a hinge pin extending diametrically through the middle of said nut and projecting therefrom at each end; a forked lever having disk-like portions pivotally mounted on the said hinge pin astride said nut, and paired links, hinge connected to the said lever and said ferrules, whereby said lever can be manipulated to turn said nut and to lock and unlock the threaded connections between said nut and said screw parts.

2. A self locking turnbuckle comprising a tubular nut having oppositely inclined internal threads at opposite ends of its bore and oppositely tapered external end portions, a pair of screw parts extending into said bore through said end portions and having external threads fitting the aforesaid internal threads, a pair of ferrules mounted on the end portions of the nut and being internally tapered complementally to said end portions, at least the tapered end portions of the nut being longitudinally slitted so as to be contractible radially, a pair of toggle means interconnecting said ferrules for moving them toward and away from one another, thereby to effect contraction and expansion of the tapered end portions and a consequent locking and release of the screw parts with respect to the nut, and means carried by the nut for actuating said toggle means in unison.

3. A self locking turnbuckle comprising a tubular nut having oppositely inclined internal threads at opposite ends of its bore and oppositely tapered external end portions, a pair of screw parts extending into said bore through said end portions and having external threads fitting the aforesaid internal threads; a pair of ferrules mounted on the end portions of the nut and being internally tapered complementally to said end portions, at least the tapered end portions of the nut being longitudinally slitted so as to be contractible radially, and toggle means operative between the nut and the ferrules for actuating said ferrules toward and away from one another in unison, thereby to effect contraction and expansion of the tapered end portions and a consequent locking and release of the screw parts with respect to the nut.

4. A self locking turnbuckle comprising a tubular nut having oppositely inclined internal threads at opposite ends of its bore and oppositely tapered external end portions, a pair of screw parts extending into said bore through said end portions and having external threads fitting the aforesaid internal threads, a pair of ferrules mounted on the end portions of the nut and being internally tapered complementally to said end portions, at least the end portions of the nut being longitudinally slitted whereby they are resilient, and means carried by said nut and interconnecting said ferrules for actuating them in unison toward and away from one another, thereby to effect contraction and expansion of the resilient portions and a consequent locking and release of the screw parts with respect to the nut, said means including an actuating lever therefor which also provides a means for turning the nut relative to the screw parts.

References Cited in the file of this patent UNITED STATES PATENTS 

